Seismic event detection system

ABSTRACT

Various embodiments herein relate to systems and methods for detecting seismic events. Systems may include inertial sensors distributed on or in communication with a network of optically switchable windows in the building. In some systems, inertial sensors are located within a window controller, within an insulated glass unit, or in some way rigidly attached to the structure of a building. Logic is described for leveraging sensed inertial data to predicted a seismic event and/or evaluate the structural health of the building. In some cases, logic may be used to issue an alert to building occupants about impending shear waves that will arrive at the building&#39;s location. In some cases, a window network may respond to a detected seismic event by, e.g., changing the optical state of windows and/or providing occupants with evacuation instructions.

INCORPORATION BY REFERENCE

An Application Data Sheet is filed concurrently with this specificationas part of the present application. Each application that the presentapplication claims benefit of or priority to as identified in theconcurrently filed Application Data Sheet is incorporated by referenceherein in its entirety for all purposes.

FIELD

The present disclosure generally relates to safety systems for buildingsand in particular to a building safety system which warns buildingoccupants before the arrival of the hazardous ground motion typicallyassociated with earthquakes and of approaching natural disasters thatcould impact an area. This advanced warning system can provide time forusers to seek shelter which may reduce bodily injury and loss of life.In addition, this system can collect and add valuable data toward ourunderstanding of earthquakes.

SUMMARY

One aspect of the present disclosure pertains to a system for detectingseismic waves in a building. The system includes: (a) a plurality ofoptically switchable windows; (b) a plurality of window controllers,each configured to control the optical state of at least one opticallyswitchable window, where the window controllers are connected via anetwork; (c) a plurality of inertial sensors, each configured to measureinertial data in at least one direction when affixed to the building andprovide the measured inertial data to the network; and (e) seismic eventdetection logic configured to (i)) identify or receive a buildingresponse signature, where the building response signature includes themeasured inertial information from the inertial sensors and (ii) analyzethe building response signature to determine that a seismic event hasoccurred. In some embodiments, the building response signature includeslocation data for each of the inertial sensors.

In some embodiments, the number of inertial sensors in a building may bebetween about 10% and about 30% of the number of optically switchablewindows of the building. In other embodiments, the number of inertialsensors in a building may be between about 30% and about 70% of thenumber of optically switchable windows of the building. In some cases,there may be more than about 2, more than about 10, or more than about50 inertial sensors in a building.

In some embodiments, at least one of the inertial sensors is locatedwithin a housing for one of the window controllers. In otherembodiments, at least one of the inertial sensors is located within ahousing for a light sensor, where the light sensor is connected thenetwork and configured to provided lighting information to the networkfor controlling the optically switchable windows.

The inertial sensors may include accelerometers and/or gyroscopes. Insome cases, the inertial sensors are MEMS devices. In some cases,accelerometers and/or gyroscopes may have a sensitivity greater thanabout 0.5 V/g, and in some cases greater than about 1 V/g. In somecases, accelerometers and/or gyroscopes may have a sample frequencygreater than about 1 kHz, and in some cases, the sampling frequency ofinertial sensors may be greater than about 2 kHz.

In some embodiments, the system includes one or more additional sensors(e.g., a strain gauge, an anemometer, a temperature sensor, apiezometer, a GPS sensor, and/or a camera) which provide additional datato the network which is included in the building response signature.

In some embodiments, at least one inertial sensor is configured toprovide inertial data to the network via a wireless connection to one ofthe widow controllers. The network may, in some cases, be configured todeliver power the window controllers and the inertial sensors. In someembodiments, at least one inertial sensor is rigidly affixed to astructural component of the building. The structural component may be,e.g., part of the building's framing structure and/or rigidly affixed tothe building's foundation. In some cases, the structural component maybe a metal beam, a concrete floor, a mullion, or a transom

In some embodiments, the seismic event detection logic is configured todetermine if a building response signature corresponds to a P-wave. Theseismic event detection logic may also be configured to determine theseismic hypocenter of the P-wave, estimate an arrival of a correspondingS-wave, or trigger an alert after determining that the building responsesignature corresponds to a P-wave.

In some embodiments, the seismic event detection logic is configured todetermine if one or more of the inertial sensors is not functioningproperly. Seismic event detection logic may be operated on a cloudcomputing platform, and in some cases, seismic event detection logic maybe operated on a distributed computing platform that includes at leastone of the window controllers. In some embodiments, the seismic eventdetection logic may be configured to receive information from anexternal earthquake event detection network.

In some embodiments, the seismic event detection logic is configured toanalyze the building response signature using a seismic model. A seismicmodel may include an expression or lookup table that relates thebuilding response signature to an occurrence of a seismic event. In somecases, the seismic model is generated using baseline signature data thatis collected from the inertial sensors.

In some embodiments, the seismic model is generated using structuralbuilding information. For example, a seismic model may be generatedbased in part on a 3D building model. In some cases, the seismic modelrepresents the building as a mass-spring-damper system. In some cases,the seismic event detection logic provides the building responsesignature to an active mass damper system when a building experienceslateral loads. Seismic detection logic may, in some cases, be configuredto detect a structural change in the building. In such cases, the logicmay also be configured to determine that the structural change creates asafety threat and trigger an alert. Triggered alerts may include audibleor visual alerts. In some embodiments, triggering an alert includesunlocking doors, closing gas lines, and/or closing water lines.

Another aspect of the present disclosure pertains to a method fordetecting seismic events in a building. The method includes operationsof at least (a)-(c). In operation (a), a window control system isinstalled in the building. The window control system includes aplurality of optically switchable windows, a plurality of windowcontrollers, and a plurality of inertial sensors. Each window controlleris configured to control the optical state of at least one opticallyswitchable window, and the window controllers are connected by anetwork. The inertial sensors are distributed in at least two dimensionsin the building, and each sensor is configured to measure inertial datain at least one direction and provide measured inertial data to thenetwork. In operation (b) a building response signature is generatedwhich includes the inertial data provided to the network. In operation(c) a seismic event is detected by analyzing the building responsesignature using seismic event detection logic.

In some cases, the building response signature includes location datafor the inertial sensors. In some cases, at least one inertial sensorincludes an accelerometer or gyroscope. In some cases, the method alsoincludes installing one or more additional sensors in the building(e.g., a strain gauge, an anemometer, a temperature sensor, apiezometer, a GPS sensor, and/or a camera), where the one or moreadditional sensors provide additional data to the network that isincluded in the building response signature.

In some cases, detecting that a seismic event has occurred includesdetecting a P-wave when analyzing the building response signature usingthe seismic detection logic. The method may also include determining theseismic hypocenter of the P-wave or estimating an arrival of acorresponding S-wave based at least in part on the building responsesignature. The method may also include an operation of triggering analert after detecting that a seismic event has occurred.

In some cases, the building response signature is analyzed by theseismic event detection logic using a seismic model. In some cases, themethod also includes an operation of detecting a structural change inthe building. In some cases, seismic detection logic is used todetermine that the structural change creates a safety threat, and analert is triggered.

These and other features of the disclosed embodiments will be describedmore fully with reference to the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a window control system that may beimplemented in a building.

FIGS. 2 a-2 d depict a building, outfitted with a plurality of inertialsensors that are configured to measure a building response signature.

FIG. 3 is a process in which inertial sensors may be used to detect aseismic event and/or structural damage in a building.

FIG. 4 is a schematic of a window controller.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following detailed description is directed to certain embodiments orimplementations for the purposes of describing the disclosed aspects.However, the teachings herein can be applied and implemented in amultitude of different ways. In the following detailed description,references are made to the accompanying drawings. Although the disclosedimplementations are described in sufficient detail to enable one skilledin the art to practice the implementations, it is to be understood thatthese examples are not limiting; other implementations may be used, andchanges may be made to the disclosed implementations without departingfrom their spirit and scope. Furthermore, while the disclosedembodiments focus on electrochromic windows (also referred to as smartwindows), the concepts disclosed herein may apply to other types ofoptically switchable devices. Additionally, the conjunction “or” isintended herein in the inclusive sense where appropriate unlessotherwise indicated; for example, the phrase “A, B or C” is intended toinclude the possibilities of “A,” “B,” “C,” “A and B,” “B and C,” “A andC” and “A, B, and C.” The terminology “designed to,” “adapted to,”“configured to,” “programmed to,” “operable to,” and “capable of” may beused interchangeably where appropriate. Such terminology is understoodto connote structure and is not intended to invoke 35 U.S.C. 112 (f).

SEISMIC EVENT—Seismic events refer to incidents in which seismic wavestravel through the earth's crust or upper mantle. At the Earth'ssurface, seismic events manifest themselves by shaking and sometimesdisplacement of ground. Typically, seismic events have a natural causesuch a rupture or movement of a geological fault to release pressure,landslides, or volcanic activity. In some cases, seismic events includeartificially produced large earth tremors that are triggered by humanactivity. For example, seismic events may be caused or triggered bylarge explosions (e.g., mine blasts and nuclear explosions), crustalshifts caused by water depletion, and fracking. In some cases, seismicevents may also trigger other disasters. For instance, when thehypocenter of a large earthquake is offshore, the seabed may bedisplaced sufficiently to cause a tsunami. In other cases, a seismicevent may trigger landslides, avalanches, and fires. While the term“epicenter” is commonly used to describe the origin of an earthquake,the more precise term “hypocenter” will be used herein. An epicenter isa point on the earth's surface directly above the hypocenter.

BUILDING—Buildings are structures that are typically suitable for humanentry and/or occupancy. Within this realm, buildings may be small orlarge structures. For example, a building may be a small dwelling, atall skyscraper, or any other sized structure. In some cases, a buildingis a fixed structure having a roof, wall, and windows.

FRAMING STRUCTURE—The framing structure refers to any integralload-bearing components that transfer the loads within a building suchas concrete slabs, beams (e.g., transoms and mullions), fasteners, andcurtain walls. The framing structure of a building transfers loadsvertically to the building's foundation and well as horizontally, e.g.,in the case of wind or a shockwave. As used herein, the buildingstructure also refers to the geometrical arrangement of these integralcomponents.

BUILDING FOUNDATION—A foundation is the element of the building whichconnects it to the ground and transfers loads from the building to theunderlying rock or soil. Foundations may be classified as shallow ordeep. Shallow foundations, sometimes referred to as footings, arefoundations in which the foundation depth is less than the buildingbreadth and also less than about 3 meters deep into the ground. In casesin which a building is massive or in which the top topsoil is weak, deepfoundations may be used. Deep foundations extend deeper than about 3meters from the surface of the ground. In some cases, piles or caissonsdriven into the ground to transfer a building's load through a weaklayer of topsoil to the stronger layer of subsoil or bedrock below.Piles or caissons may penetrate through several meters to bedrock, butsometimes they do not reach bedrock.

OPTICALLY SWITCHABLE WINDOW—Optically switchable windows exhibit acontrollable and reversible change in an optical property when astimulus is applied, e.g., an applied voltage. The optical property istypically one or more of color, transmittance, absorbance, andreflectance. Electrochromic (EC) devices are sometimes used in opticallyswitchable windows. One well-known electrochromic material, for example,is tungsten oxide (WO₃). Tungsten oxide is a cathodic electrochromicmaterial in which a coloration transition, transparent to blue, occursby electrochemical reduction. Optically switchable windows, whetherelectrochromic or otherwise, may be used in buildings to controltransmission of solar energy and thus heat load imposed on the interiorof the building. The control may be manual or automatic and may be usedfor maintaining occupant comfort while reducing the energy consumptionof heating, air conditioning and/or lighting systems. Examples ofoptically switchable windows are presented in U.S. patent applicationSer. No. 12/645,111, filed Dec. 22, 2009, and titled “FABRICATION OF LOWDEFECTIVITY ELECTROCHROMIC DEVICES,” and in PCT Published ApplicationNo. WO2015168626, filed May 1, 2015, and titled “ELECTROCHROMIC DEVICES”which are herein incorporated by reference in their entirety.

WINDOW CONTROLLER—Window controllers are units responsible for applyinga current and/or voltage to one or more electrochromic windows, e.g., ina building. Windows may be grouped or zoned, be on different sidesand/or floors of a building. Generally, window controllers receive acontrol signal specifying the tint level that is to be applied to theelectrochromic windows. In some embodiments, such control signals arepassed over a window network and originate from sources such asuser-controlled input, window network tint intelligence, and/or abuilding management system (BMS). Examples of window network tintintelligence are presented in both U.S. patent application Ser. No.15/347,677, filed May 7, 2015, and titled “CONTROL METHOD FOR TINTABLEWINDOWS”, and International PCT Application PCT/US16/41344, filed Jan.12, 2017, and titled “CONTROL METHOD FOR TINTABLE WINDOWS,” each ofwhich is herein incorporated by reference in its entirety.

In certain embodiments, a window controller is placed near theelectrochromic window (e.g., within about 1 meter of the edge of thewindow), adjacent to, on the glass or inside a window, or within a frameof the self-contained assembly. In some embodiments, a window controlleris part of a window assembly, a window or laminate. In some cases, awindow controller is attached to a structural component of a building;e.g., a steel I-beam or a concrete slab. Further examples of windowcontrollers and their features are presented in International PatentApplication No. PCT/US17/20805, filed Mar. 3, 2017, and titled “METHODOF COMMISSIONING ELECTROCHROMIC WINDOWS”; U.S. patent application Ser.No. 15/334,835, filed Oct. 26, 2016, and titled “CONTROLLERS FOROPTICALLY-SWITCHABLE DEVICES”; and U.S. patent application Ser. No.13/449,248, filed Oct. 17, 2013, and titled “CONTROLLER FOROPTICALLY-SWITCHABLE WINDOWS”; each of which is herein incorporated byreference in its entirety.

WINDOW CONTROL SYSTEM—When a building is outfitted with opticallyswitchable windows, window controllers may be connected to one anotherand/or other entities via a communications network sometimes referred toas a window control network. The network and the various devices (e.g.,controllers and sensors) that are connected via the network (e.g., wiredor wireless power transfer and/or communication) are referred to hereinas a window control system. Window control networks may provide tintinstructions to window controllers, provide window information to mastercontrollers or other network entities, and the like. Examples of windowinformation include current tint state or other information collected bywindow controller. In some cases, a window controller has one or moreassociated sensors that provide sensed information over the network.Sensors and other devices that are part of a window control system needhave a direct impact on window control. For example, logic forcontrolling the optical states of windows may not consider the output ofinertial sensors, yet these sensors are still considered part of thewindow control system. In some cases, one or more sensors are connectedto the network independently of a window controller. Examples of sensorsthat may provide information over a window controller network includephotosensors, temperature sensors, occupancy sensors and inertialsensors. A sensor unit for providing lighting data may be located on arooftop of a building, e.g. as described in U.S. patent application Ser.No. 15/287,646, filed Oct. 6, 2016, and titled “MULTI-SENSOR,” which isherein incorporated by reference in its entirety. Such sensors mayobviate the need for optical sensors at the window location and thusmake the window control system much less complex than those that rely onmultiple sensors at the window's physical location.

FIG. 1 provides an example of a control network 101 of a window controlsystem. The network may distribute both control instructions andfeedback, as well as serving as a power distribution network. A mastercontroller 102 communicates and functions in conjunction with multiplenetwork controllers 104, each of which network controllers is capable ofaddressing a plurality of window controllers 106 (sometimes referred toherein as leaf controllers) that apply a voltage or current to controlthe tint state of one or more optically switchable windows 108. In someimplementations, the master controller issues the high-levelinstructions (such as the final tint states of the electrochromicwindows) to the network controllers, and the network controllers thencommunicate the instructions to the corresponding window controllers.Typically a master controller is configured to communicate with one ormore outward face networks 109.

In some embodiments, outward facing network 109 is part of or connectedto a building management system (BMS). A BMS is a computer-based controlsystem that can be installed in a building to monitor and control thebuilding's mechanical and electrical equipment. A BMS may be configuredto control the operation of HVAC systems, lighting systems, powersystems, elevators, fire systems, security systems, and other safetysystems. BMSs are frequently used in large buildings where they functionto control the environment within the building. For example, a BMS maymonitor and control the lighting, temperature, carbon dioxide levels,and humidity within the building. In doing so, a BMS may control theoperation of furnaces, air conditioners, blowers, vents, gas lines,water lines, and the like. To control a building's environment, the BMSmay turn on and off these various devices according to rules establishedby, for example, a building administrator. One function of a BMS is tomaintain a comfortable environment for the occupants of a building. Insome implementations, a BMS can be configured not only to monitor andcontrol building conditions, but also to optimize the synergy betweenvarious systems—for example, to conserve energy and lower buildingoperation costs. In some implementations, a BMS can be configured with adisaster response. For example, a BMS may initiate the use of backupgenerators and turn off water lines and gas lines.

In some embodiments, network 109 is a remote network. For example,network 109 may operate in the cloud or on a device remote from thebuilding having the optically switchable windows. In some embodiments,network 109 is a network that provides information or allows control ofoptically switchable windows via a remote wireless device. In somecases, network 109 includes seismic event detection logic. Furtherexamples of window control systems and their features are presented inU.S. patent application Ser. No. 15/334,832, filed Oct. 26, 2016, andtitled “CONTROLLERS FOR OPTICALLY—SWITCHABLE DEVICES” and InternationalPatent Application No. PCT/US17/62634, filed on Nov. 23, 2016, andtitled “AUTOMATED COMMISSIONING OF CONTROLLERS IN A WINDOW NETWORK,”both of which are herein incorporated by reference in its entirety.

INERTIAL SENSOR—Inertial sensors are electronic devices that measure andreport linear and/or rotational accelerations. Accelerometers aresensors that measure linear acceleration and gyroscopes are sensors thatmeasure rotational acceleration. Microelectromechanical systems (MEMS)type accelerometers and gyroscopes are frequently found in devices suchas automobiles and mobile devices. A single sensor unit may measurelinear and/or rotational acceleration along one, two, or three axes. Forinstance, many smartphones, such as the Apple iPhone™, include aninertial sensor that measures linear and rotational acceleration aboutthree axes. When placed in a building or other structure, inertialsensors may be used to detect vibrations and movements resulting fromseismic waves or other sources.

While the present disclosure is provided with micro-electronic inertialsensors in mind, any sensor known now, or later developed, which can beused for monitoring the dynamic response of a building can also be used.For example, future developments in geolocation technology (e.g., GPS)may be sensitive enough for seismic detection systems. In some cases,the movement of a building may be measured optically, or by monitoringthe strain in a building's framing structure using strain gauges. Insome embodiments, an inertial response of a building is monitored usinga combination of different types of sensors at one or more locations ina building to provide more accurate or reliable inertial data then wouldbe otherwise be had. All such systems and methods for measuring theinertial response of a building are meant to fall within the scope ofthis disclosure.

BUILDING RESPONSE SIGNATURE—A building response signature refers to theinertial data collected by inertial sensors at a plurality of locationswithin a building; e.g., on various floors of a building. A buildingresponse signature records inertial data at various locations in abuilding when the building reacts to a stimulus. For example, a buildingresponse signature may record common events such as a truck rumblingdown an adjacent road, high winds, nearby jackhammering, a fireworksdisplay, mining or construction activity including use of explosivesand/or heavy machinery, vibrations from an underground or adjacentparking garage, and normal business day occupancy. Any one orcombination of these or other sources of vibration may constitute abuilding's response signature. A building response signature may be usedto record inertial measurements corresponding to more serious eventssuch as P-waves and S-waves from an earthquake. In some cases, abuilding response signature may refer all of the inertial data collectedin a building corresponding to a particular event. For example, abuilding response signature may correspond a period of time, e.g., forabout 10 seconds after the event, in which motion is detected. In somecases, a building response signature may include historical inertialdata of a building. Using a building response signature, seismic eventdetection logic may be used to determine the dynamic conditions of abuilding. In some cases, a building response signature may be analyzedto characterize a structural change within a building. In some cases, abuilding response signature may be analyzed to characterize a seismicevent or another event causing motion within a building. In some cases,the building response signature is normalized by, for example, applyinga baseline response of the building. As an example, the normalizingbaseline response may be obtained from data collected as a continuousstream of measurements taken by inertial sensors within a building.

SEISMIC MODEL—A seismic model is used to classify stimuli based uponinertial measurements in a building response signature. Generallyspeaking, a seismic model makes use of a building's structuralproperties so that inertial data measured throughout a building may beinterpreted collectively. A seismic model may include lookup tables,expressions, computer-aided engineering models of a building, and thelike. In some cases, a seismic model returns one or more outputs when abuilding response signature is provided as an input. For example, aseismic model may output classifications of events that may have causedbuilding movement. Certain ranges or patterns found within inertial dataof a building response signature may be correlated to windstorms,earthquakes, and the like. In some cases, a seismic model may be used todetermine a structural change within a building. A building responsesignature in which a shift in a building's natural frequency is observedmay be correlated to structural damage or building renovation. In somecases, a seismic model may correlate inertial data to loads and/orstresses experienced by structural components that might lead to failureof components within a building. In some cases, a seismic model may beused by seismic event detection logic to determine if a seismic eventhas occurred, or if there has been a structural change within abuilding.

SEISMIC EVENT DETECTION LOGIC—Seismic event detection logic is logicthat, when executed, processes data from a plurality of inertial sensorsand determines whether a seismic event has occurred. When the inertialsensors are provided in a single building, this data may be provided asa building response signature. In some cases, seismic event detectionlogic may make a determination of a seismic event by inputting abuilding response signature into a seismic model to collectivelyinterpret inertial data from various locations withing of a building.Certain building response signatures are produced only or primarily whenthe building is responding to a seismic event. In some implementations,the seismic event detection logic is designed or configured todiscriminate between building response signatures produced by seismicevents and those produced by other stimuli. Regardless of whether abuilding response signature is determined, the seismic event detectionlogic discriminates between building sensor data produced by typicalnon-threatening events and seismic events. In some cases, the logic isdesigned or configured to predict the magnitude and epicenter and/orhypocenter of a seismic event. In some cases, the logic is designed orconfigured to identify fast traveling pressure waves produced by aseismic event. Upon identifying such waves, the logic may determine thatslower traveling shear waves are approaching a building and will soonarrive. In some cases, the logic is designed or configured to predicthow soon the shear waves will arrive. In certain embodiments, the logicis configured to send out an alert, e.g., to building occupants, newsoutlets, state agencies, emergency responders, other building systems,other buildings, mobile devices, and the like.

When processing data from a plurality of inertial sensors, seismic eventdetection logic may use algorithms and models such as those known by oneof ordinary skill in the art. When processing data, seismic eventdetection logic may make use statistical processes such as linearregression, logistic region, ordinary least square regression, andpolynomial regression. In some cases, the logic is implemented as aneural network. In some cases, seismic event detection logic usesmachine learning methods (including deep learning methods) that allowthe logic to improve over time, e.g., by monitoring the buildingresponse signature due to non-threatening events such as a mildwindstorm, mining or construction activity, or other events that impartinertial activity to the building.

It will be appreciated by one of skill in that art that that seismicevent detection logic, may be implemented using computer code written inany programming language that can be executed on a computer systemand/or server or server system such as, for example, C, C++, HTML,Java™, JavaScript, ActiveX, Python, and Ruby on Rails. Seismic eventdetection logic may be implemented using hardware, software, firmware,and various combinations thereof. The code for seismic event detectionlogic may be in any other volatile or non-volatile memory medium ordevice as is well known, such as a ROM or RAM, or provided on any mediacapable of storing program code, such as any type of rotating mediaincluding floppy disks, optical discs, digital versatile disk (DVD),compact disk (CD), microdrive, and magneto-optical disks, and magneticor optical cards, nanosystems (including molecular memory ICs), or anyother type of computer-readable medium or device suitable for storinginstructions and/or data. Additionally, the entire program code forseismic event detection logic, or portions thereof, may be transmittedand downloaded from a software source over a transmission medium, e.g.,over the Internet, or from another server, as is well known, ortransmitted over any other conventional network connection as is wellknown (e.g., extranet, VPN, LAN, etc.) using any communication mediumand protocols (e.g., TCP/IP, HTTP, HTTPS, Ethernet, etc.) as are wellknown.

ALERTS—Alerts are sent to warn individuals or systems that future damageor danger is possible or likely. Seismic event detection logic maytrigger alerts to warn building occupants or nearby emergency personnelof approaching seismic waves or of damage incurred by a seismic event.Alerts may be given using strobing lights, sirens, an audio messagerelayed by an intercom, lights instructing occupants to a building exit,alerts to mobile devices, and the like.

General Description

One aspect of the present disclosure relates to buildings or otherstructures outfitted with a plurality of inertial sensors. In somecases, a building may be outfitted with a plurality of opticallyswitchable windows having associated inertial sensors. A window may beassociated with an inertial sensor when a window controller thatcontrols the tint state of an optically switchable window also receivesinformation from the inertial sensor. In some embodiments, the windowcontroller contains the inertial sensor, while in other embodiments theinertial sensor is associated with the smart window in another way, suchas where the inertial sensor is integrated into the window construction.For example, an insulated glass unit could have one or more inertialsensors in the secondary seal area, in the spacer, or on the glass(e.g., inside the IGU or outside the IGU). By using inertial sensorsplaced throughout a building, the dynamic response of a building ismeasured. The measured response is recorded as a building responsesignature. Using seismic event detection logic, a building's responsesignature may be analyzed to characterize seismic events and/or otherevents causing building motion. In some cases, seismic event detectionlogic may identify from a building response signature that additionalseismic waves are arriving and inform earthquake warning systems, damagemitigation systems, and the like. One embodiment is a window controlsystem including one or more inertial sensors configured for detectionof seismic activity. The one or more inertial sensors may be associatedwith window controllers of the building, e.g., leaf controllers, networkcontrollers and/or master controllers. The one or more inertial sensorsmay also be, in addition or alternatively, associated with a sensor,e.g., individual window sensors and/or a rooftop sensor, used to collectlight data for the window control system. In one embodiment, the one ormore inertial sensors are configured in a rooftop sensor such as thosecommercially available from View, Inc. of California, and described inU.S. patent application Ser. No. 15/287,646, filed Oct. 6, 2016, andtitled “MULTI-SENSOR,” which is herein incorporated by reference in itsentirety. In certain instances, it is advantageous to have many inertialsensors, e.g., included in many or all leaf controllers and/or lightsensors of a window control system, in order to collect as much seismicdata as possible from a number of locations in the building. In otherinstances, one or more inertial sensors in a rooftop light data sensormay be sufficient, given widespread adoption of tintable glazings and,e.g., where many buildings each have a rooftop sensor so equipped. Inall such cases, a seismic detection grid or network is created, when theinertial sensor data is used collectively.

A naturally-occurring earthquake happens when tectonic forces releasestored elastic strain energy along a geological fault. Material on oneside of a fault moves in relation to the other side of the fault.Sliding starts at a location, known as the hypocenter, and propagates ineither direction along the fault surface. The speed of a fault tear isslower and distinct from resultant pressure and shear waves that areemitted. In a normal fault, tensional forces cause extension and thematerial above the fault to move downward relative to the materialbeneath the fault. In a reverse fault, the compressional forces causethe material above the fault to move upward relative to the materialbeneath the fault. In a strike-slip fault, shearing forces cause thematerial on one side of the fault to move horizontally relative to thematerial on the other side. A fault that is best described as acombination of these classifications may be described as an obliquefault. Each of these fault types provides the potential for producingdestructive seismic waves, and each produces P-waves in advance ofS-waves.

Pressure waves, also called primary waves or “P-waves,” arecompressional waves that are longitudinal in nature. Shear waves alsocalled secondary waves or “S-waves,” are transverse in nature and onlytravel through solid materials that support shear stresses. S-waves areslower than P-waves, and speeds are typically around 60% of that ofP-waves in any given material. P-waves are usually undetectable by humansenses or are merely felt as an initial jolt, while S-waves may generateperiodic motion (typically at about 1 Hz) that is more damaging tobuildings and other structures. Damaging effects of S-waves are oftenmagnified when a building has a resonant period similar to that of theshear waves. These waves are strongest at the ends of the slippage andmay project destructive waves at great distances beyond the hypocenter.The intensity of propagating seismic waves may be highly dependent onfactors such as the soil conditions in the region.

Since P-waves travel faster than S-waves, P-waves may be used to detecta seismic event before the arrival the more destructive S-waves. Usingseismic event detection logic which receives data from an associatedseismic detection system described herein, an identified P-waves maytrigger an alert system of an impending earthquake, more specifically,the future arrival of S-waves. Due to the delay of the S-waves, buildingoccupants may be warned by an alert of an impending quake seconds orminutes before the shaking begins. Having a warning alert system, evenif only seconds before shaking beings, may be the difference betweenlife and death for building occupants and/or individuals in surroundingareas. For example, a warned occupant may have time to find shelterwithin a room or evacuate a building before severe shaking beings. Evena few seconds before a mild tremor might be enough time to alert asurgeon to wait to make a delicate incision during a surgical operation.Alert systems may also be configured to close gas lines and water lines,reducing fire or flooding risks within the building.

System

FIGS. 2 a-2 d depict a building, outfitted with a plurality of inertialsensors that are configured to measure a building response signature.Shown in FIG. 2 a, building 220 may be outfitted with opticallyswitchable windows 208 that have associated inertial sensors. Inertialsensors may include accelerometers, inclinometers, gyroscopes, and thelike. In some cases, additional sensors such as strain gauges, occupancysensors, or temperature sensors may be used to provide information thatis included in a building response signature.

An inertial sensor may be located, e.g., at any place where the sensormay be rigidly coupled to the framing structure of a building. Windowsare often closely coupled to the framing structure of a building, makingthem a convenient location to attach inertial sensors. In some cases,inertial sensors are attached to a window frame, located within a windowcontroller unit, or located on the window glass. When a windowcontroller is configured with inertial sensors, a window controller maybe attached to the window frame itself, or attached to a nearbystructural component of the building. In some cases, inertial sensorsand/or other sensors may be attached to a support beam, a concrete slabor other another component within the wall of a building that isaccessed during window installation but would ordinarily be hidden fromview. In some cases, inertial sensors may be attached to mullion or atransom. In some cases, inertial sensors are rigidly affixed to thebuilding's foundation. In some cases, inertial sensors are affixed toone or more light sensors that are part of or associated with the windowcontrol system. In some cases, inertial sensors are remote from anassociated window or window controller. For example, an inertial sensormay be rigidly attached to the framing structure of a building andconfigured to receive power and/or transmit data to a nearby windowcontroller by wire. In some cases, inertial sensors may receive powerand/or transmit data wirelessly to a nearby window controller. In somecases, a sensor may receive power wirelessly. Examples of wireless powerdelivery systems are presented in U.S. patent application Ser. No.62/402,957, filed Sep. 30, 2016, and titled “WIRELESS POWEREDELECTROCHROMIC WINDOWS” which is herein incorporated by reference in itsentirety. Examples of window antennas that may be used for wirelesspower delivery are presented in International Patent Application No.PCT/US17/31106, filed May 4, 2017, and titled “WINDOW ANTENNAS” which isherein incorporated by reference in its entirety.

In some embodiments, a plurality of inertial sensors may be incommunication (e.g., wire or wireless communication) with various windowcontrollers (e.g., master controllers, network controllers, and leafcontrollers) and other devices (e.g., light sensors) of the windowcontrol system, such that inertial data from the plurality of inertialsensors may be easily aggregated into a building response signature.Examples of control networks used by the window control system aredescribed elsewhere herein. In some cases, inertial sensors may providean analog or digital signal of measured linear acceleration data alongone, two, or three axes. In some cases, inertial sensors may providerotational acceleration data about one, two, or three axes. In somecases, sensors may provide integrated values of linear velocity anddisplacement and/or rotational velocity and displacement correspondingto one, two, or three axes.

In one embodiment, inertial sensors are provided within the housing of awindow controller. Alternatively or additionally, inertial sensors maybe located in the housing of other controllers in the window controlnetwork, for example, in a network controller, a master controller,and/or a control panel. In some embodiments, inertial sensors may belocated in or associated with one or more light sensors that are part ofor associated with a window control system. In other embodiments, aplurality of inertial sensors are configured both in window controllers(leaf, network, master or other) and in light sensors of the windowcontrol system. Any of these locations may provide suitable housing andinfrastructure for inertial sensors, provided they are sufficientlyrigidly coupled to building. In addition to providing power to inertialsensors and transmission of inertial data, a window control network mayprovide resources that can be leveraged by seismic event detectionlogic. For example, when a window control system is commissioned, thelocation of various windows and window controllers are mapped throughoutthe building. This location information, which is generally available ona window control network, may be incorporated into a building responsesignature and used by seismic event detection logic. In some cases, awindow control system may have indoor or outdoor temperature sensorsthat inform seismic event detection logic. For example, measuredtemperatures may be used to provide temperature compensation informationfor inertial measurements, or to adjust an expected building responsesignature due to thermal variations. In another example, if seismicevent detection logic identifies that sensors are non-functional or haveirregularities, the logic may provide a report to a facilities managerindicating which sensors need maintenance.

Inertial sensors are typically distributed in at least two dimensionswithin a building. For example, sensors may be associated with windowson facades facing different directions. In a multistory building,inertial sensors may be distributed amongst floors. FIG. 2 b depictsseveral floors 222 of a multistory building in which inertial sensors,associated with windows 208, are distributed in by x and y directions.In this manner, windows 208 provide a series of data collection pointson the surface of the building for accurately recording thethree-dimensional movement into the building response signature. In someembodiments, interior windows may also have associated inertial sensors.In some embodiments, data for a building response signature may also becollected by sensors that are not on a window network. For example,inertial sensors may be located in a subterranean parking garage orwithin the foundation of the building. In some cases, a building mayalso be equipped with additional sensors that can be correlated tobuilding motion such as strain gage sensors, GPS sensors, cameras, windsensors, temperature sensors, and the like. In certain embodiments,inertial sensors of the window systems described may or may notcoordinate with other inertial sensors of the building (or otherbuildings or locations, such as inertial sensors in the earth).

The number of inertial sensors a building is equipped with may varydepending on factors such as the building's size, construction, shape,height, complexity, and location. For example, a building may beequipped with inertial sensors at more than 3 locations, in some casesmore than about 20 locations, and in some cases more than about 100locations. In some cases, inertial sensors may be associated with about10% to about 30% of the exterior windows of a building, in some casesinertial sensors may be associated with about 30% to about 70% of theexterior windows, and in some cases inertial sensors may be associatedwith greater than about 70% of the exterior windows. In some cases,inertial sensors may be associated with between about 10% and about 30%,between about 30% and about 70%, or greater than about 70% of thecontrollers on a window control system. In some cases, inertial sensorsmay associated with more than about 20%, more than about 50% or morethan about 90% of the light sensors in a building.

In some cases, inertial sensors are MEMS accelerometers. In some cases,MEMS accelerometers have a self-noise level that is less than about 1μg/√Hz, in some cases less than about 10 ng/√Hz, and in some cases lessthan about 1 ng/√Hz. If providing an analog output signal, inertialsensors may have a sensitivity that is greater than about 0.5 V/g,greater than about 1 V/g, and in some cases greater than about 5 V/g. Insome cases, a MEMS accelerometer has a sampling rate greater than about1 kHz, in some cases greater than about 2 kHz, and in some cases greaterthan about 4 kHz.

FIGS. 2 c and 2 d depict how distributed inertial sensors along both xand y coordinates may be collectively used to characterize a seismicevent. A multistory building is depicted having floors 222 and 223.These floors have optically switchable windows with associated inertialsensors 208 (not shown in floor 223) that measure an inertial response.The magnitude of this inertial response is graphically depicted byarrows 232 x in floor 223.

FIG. 2 c depicts an example of a P-wave 230 passing through the groundunderneath floors 222 and 223 in a building. The spacing of the lines inwave 230 is representative of the pressure gradient within the wave. Asdepicted, the wave's highest pressure gradient is centered underneaththe building, and the measured inertial response is illustrated byarrows 232 x. By analyzing the inertial response, properties includingthe speed, orientation, and magnitude of the seismic wave may bedetermined. In some cases, if seismic event detection logic interprets abuilding response signature as being representative in of a P-wave, analert to may be triggered to warn building occupants of an approachingS-wave.

FIG. 2 d depicts an example of an S-wave 231 passing through the groundunderneath floors 222 and 223 of the building considered in FIG. 2 c.S-wave 231 passes under the building at some time after P-wave 230passes under the building. The shear wave results in displacement thatis transverse to the wave direction. As drawn, inertial sensorsdistributed on one or more floors may record wave 231 as it passesthrough the building. These inertial measurements may then be analyzedto determine the strength of the wave, and for damages that may haveoccurred to the building. As depicted, the measured inertial response isillustrated by arrows 232 z.

Seismic event detection logic may be used to discriminate seismic eventsignatures (e.g., P-waves) and non-seismic event signatures. As anillustration, if a large object is dropped in a building, the resultingmotion may be detected nearby but not elsewhere. In some cases, abuilding response signature might record a single area showing aheightened response that quickly dissipates away from the event origin.By analyzing the building response signature, seismic event detectionlogic may determine that no seismic event has occurred. Alternatively,if a seismic event does occur, a consistent wavefront across a pluralityof inertial sensors (e.g., as shown by measured responses 232 x and 232z in FIGS. 2 c and 2 d, respectively) may be recorded in the buildingresponse signature and identified as a seismic event by seismic eventdetection logic. In some cases, seismic event detection logic may beable to determine information about the wave including the amplitude ofthe seismic wave and the direction of propagation.

Seismic event detection logic may be deployed at a number of locationsincluding but not limited to, a network controller, a master controller,a remote device, and/or the cloud. In some embodiments, a plurality ofcontrollers in a window control system may function together as adistributed computing platform, and the seismic event detection logicoperates on the distributed computing platform. Window control systemsthat provide distributed control platforms are further described in U.S.Provisional Application No. 62/607,618, filed Dec. 19, 2017, and titled“ELECTROCHROMIC WINDOWS WITH TRANSPARENT DISPLAY TECHNOLOGY FIELD,”which is herein incorporated in its entirety. In some embodiments, abuilding response signature may be sent to the cloud or to a remotecomputer where seismic event detection logic analyzes the buildingresponse signature. In some cases, this may occur at intervalscorresponding to when motion is detected. In some cases, inertial datamay be processed by seismic event detection logic in real time. In somecases, inertial data may be transmitted over a window control network inless than 1 second, in some cases less than 100 milliseconds, and insome cases less than 10 milliseconds. In some cases, such as whenbuildings have the same owner or are equipped with the same type ofwindow control system, building response signatures from all buildingsmay be simultaneously processed by seismic control logic on a singlecloud device, thereby improving accuracy for size and location of animpending earthquake. In some cases, seismic event detection logic mayreport to or receive information from other quake detection networks,e.g., the collaborative Quake-Catcher Network, or USGS seismographicnetwork. To this end, examples of remote monitoring systems aredescribed in U.S. patent application Ser. No. 15/123,069, filed Mar. 5,2015, and titled “MONITORING SITES CONTAINING SWITCHABLE OPTICAL DEVICESAND CONTROLLERS,” which is herein incorporated by reference in itsentirety. Examples of consoles where the seismic detection logic may bedeployed are presented in International Patent Application No.PCT/US17/54120, filed Sep. 28, 2017, and titled “SITE MONITORINGSYSTEM,” which is herein incorporated by reference in its entirety.

Methods of Using Inertial Sensors in a Building

FIG. 3 provides a flowchart 340 of a process where inertial sensors maybe used to detect a seismic event and/or structural damage in abuilding. In step 341 a seismic model is created. Generally, step 341 isperformed during construction of a building or when retrofitting abuilding with inertial sensors. A seismic model is used by seismic eventdetection logic to interpret measured inertial data. For example,measured inertial data may be input into the seismic model which inreturn outputs information characterizing the event that has caused themotion. In some cases, a seismic model may relate measured inertial datato locations on a building. In some cases, a seismic model may includean expression or lookup table relating inertial responses to dynamicconditions of a building. In some cases, a seismic model may relatemeasured inertial data to loads and/or stresses experienced bystructural components, e.g., by accounting for the stiffness in abuilding's framing structure. In some cases, a seismic model may providerelationships between a shift in resonant frequency and structuralfailures.

In some embodiments, a seismic model is created using structuralbuilding information 342. For example, a seismic model may be createdusing architectural drawings or a 3D building model. 3D building modelsmay be generated using computer-aided engineering software such asANSYS, ABAQUS, AutoCAD Civil 3D, Revit and the like. 3D building modelsare created when designing a building, or at a later time such as when abuilding undergoes a major renovation. In some cases, 3D building modelsare updated to reflect changes in the building structure. These modelsprovide an accurate representation of the building and includeinformation relating to, e.g., the materials used in the building, theconstruction of the building, and the dimensions of the building. Insome cases, the dimensional information of a 3D building model may beaccurate to within a few centimeters of the physical buildingdimensions. In some embodiments, a seismic model may be generatedautomatically when seismic detection logic analyzes a 3D building model.Analysis of a 3D building model may, e.g., be used to determine thebuilding's natural frequency and/or displacement thresholds that wouldbe indicative of building damage. In some cases, the seismic detectionlogic is packaged as a module that is executed by a facilitiesmanagement application. A facilities management application is asoftware tool that may be used to, e.g., commission a window networkand/or generate a graphical user interface for controlling opticallyswitchable windows. In some cases, the seismic detection logic mayreference the same 3D building model file that is also used for otherfunctions of the facility management application. Facilities managementapplications and 3D building models are further described inInternational Patent Application No. PCT/US17/62634, filed on Nov. 23,2016, and titled “AUTOMATED COMMISSIONING OF CONTROLLERS IN A WINDOWNETWORK,” which is herein incorporated by reference in its entirety.

Alternatively or additionally, a seismic model may be created byestablishing a baseline signature of inertial data 343. For example, abuilding may be monitored for a period to determine inertialmeasurements corresponding benign events such as wind or occupantactivity. After the baseline signature data is collected, a seismicmodel may be used to interpret building response signatures that fallwithin predetermined ranges as corresponding to non-threatening events.

When motion is detected by inertial sensors, a building responsesignature is recorded 344. Seismic event detection logic is thenoperated 345 to determine if a seismic event has occurred 346, or ifthere has been a structural change in the building 348. When the seismicevent detection logic is executed, inertial sensors may continue tomeasure movements or vibrations in step 344. Generally, step 344 is aprocess that runs indefinitely once the system is configured. Forexample, a building response signature may include a continual stream ofinertial data, or sensors may continually monitor for movements torecord in a building response signature. In step 345 seismic eventdetection logic uses a seismic model to analyze a building responsesignature and determine if a seismic event has occurred. In some cases,seismic event detection logic may input inertial data into a seismicmodel. In some cases, seismic event detection logic may simply compareinertial data to baseline signature data. In some cases, seismic logicmay receive information from one or more external earthquake detectionnetworks (e.g., the Quake-Catcher Network, the USGS seismographicnetwork, or another window-based network) that are used to confirmand/or characterize a seismic event. For example, the time differentialbetween when P-waves are detected in a building and one or more otheradditional measurement locations that are provided over an externalearthquake detection network may be used to determine the hypocenterand/or the estimated time at which S-waves will arrive. In some cases,the seismic event detection logic may have a confidence threshold whichmust be met in determining whether a seismic event has occurred. In somecases, seismic event detection logic may use statistical means toanalyze large quantities of inertial data.

If seismic event detection logic determines that a seismic event hasoccurred, alert 347 will be triggered. In some cases, alert 347 willonly be triggered if a seismic event is determined to have a criticalstrength, or pose a danger to building occupants. In some cases, ifseismic detection logic has determined a structural change in a buildingthat makes it seismically unsafe, the critical strength or thresholdlimits before an alert is triggered may be reduced. For example, if thebuilding structurally deteriorates (gradually or abruptly), a predictedearthquake magnitude that triggers an alert may decrease. As anillustrative example, the threshold magnitude of a quake may be a 4.0 or6.0 on the Richter scale depending on the recognized structuralintegrity of the building in question. If a building that once couldwithstand a magnitude 6.0 earthquake can no longer do so for any reason,the logic may need to be adjusted so that an alert is triggered when theseismic model predicts a magnitude 4.0 or above earthquake. Alert 347may be transmitted from seismic event detection logic to a BMS, to abuilding alert system, to building occupants through a mobile app, andthe like. In some cases, an alert may contain an analysis of the seismicevent, such as the magnitude of a seismic event, or a prediction of animpending seismic event. In some cases, an alert may provide buildingoccupants with an amount of time until S-waves arrive. In some cases,occupancy and/or inertial information may be used to coordinate ordetermine escape patterns for occupants for saving the most buildingoccupants as possible, and an alert may instruct building occupants ofthese optimize escape routes. For example, a building response signaturemight indicate a particular escape route is unsafe, or occupancy sensorsmay indicate that a particular escape route may accommodate more peoplebecause of low building occupancy detected in that portion of abuilding. In some cases, an alert may shut off gas or fire lines. Insome cases, an alert may alert emergency personnel. Alerts may also beused to send control signals to the electrochromic windows, e.g., whenseismic events are detected. Controllers may be programmed to clear allthe windows so that, e.g., emergency personnel can see into the buildingmore easily and visually communicate with people inside the building ifneeded. In some cases, only windows where occupants are detected arecleared while windows while other windows remain tinted to helpemergency personnel identify where building occupants are located in abuilding. In another example, windows are tinted to prevent heat gain onone or more sides of a building when the cooling system is shut down,impaired, or expected to be impaired due to loss of power ormalfunction/damage from a seismic event. Additional examples ofcontrolling window systems in response emergency situations (such aspower emergency scenarios), that can be implemented after a seismicevent are described in U.S. patent application Ser. No. 15/739,562,filed Dec. 12, 2017, and titled “POWER MANAGEMENT FOR ELECTROCHROMICWINDOW NETWORKS,” which is herein incorporated by reference in itsentirety. After transmitting alert 347, or after determining that noseismic event has occurred, seismic event detection logic may beconfigured to determine whether a structural change has occurred. Forexample, seismic event detection logic may be used to determine failurewithin a joint or weld by monitoring changes in inertial data over time.If no structural change is detected, the process returns to measuring abuilding response signature when motion is detected. If a structuralchange is detected, alert 348 is triggered. Alert 348 may be transmittedfrom seismic event detection logic to a BMS, to a building alert system,to building occupants through a mobile app, and the like. Generally, thedescription regarding the alert in step 347 also pertains to the alertin step 348. If structural damage compromising the safety of buildingoccupants is detected, instructions may be provided that requestimmediate evacuation. If a non-threatening structural change isdetected, an alert may be sent to a building administrator suggestingfurther investigation. In cases where a structural change is deemedpermanent or non-threatening, e.g., if a building is undergoingrenovation, the seismic model may be updated 350, and the processreturns to observing movements and measuring a building signature 344.

In some cases, a multi-story building may be modeled, in step 341 ofprocess 340, as a mass-spring-damper system. While often thought of asbeing extremely rigid, a tall building may allow for a significantamount of sway under normal conditions. For instance, a building having100 floors may sway on the order of several feet in a windstorm. Whenmodeled as a complex mass-spring-damper system, the relationshipsbetween inertial data collected on different levels may be used toprovide greater insight into an event causing building motion. Indetermining if a seismic event has occurred, seismic event logic maylook for patterns between inertial data on different floors. Forinstance, when a seismic wave is recorded on the ground floor of abuilding the inertial sensors on a higher level may be expected to havea delayed response and measure a greater displacement. In some cases, ifsensors on upper stories do not reflect a predetermined pattern, then aseismic event may be ruled out as a possibility. In some cases, seismiclogic may account for the current motion of a building when analyzingsubsequent inertial measurements. For example, if a building experiencesmotion due to a windstorm, that motion may be taken into account whendetermining if a building response signature corresponds to a seismicevent. In some embodiments, amplified signals (due to building sway) onthe uppers stories of a multi-story building may lead to a greatersensitivity in measuring P-waves and S-waves.

In some embodiments, seismic event detection logic may make use ofnon-inertial information included in a building response signature. Insome cases, measurements from an anemometer may be used to estimate theforce applied by the wind on a building. By knowing the force applied bythe wind some or all of sensed motion in a building signature may beaccounted for. In some cases, temperature sensors may be used to providetemperature compensation for other sensors (e.g., strain gauges, orinertial sensors). In some cases, GPS sensors, strain gauges, or camerasystems may be used to verify building displacements recorded byinertial sensors. In some cases, a building response signature mayinclude data from inertial sensors that are not connected to a windowcontroller, e.g., inertial sensors may be located in an undergroundparking garage. In some cases, a building response signature may includeinformation relating to soil conditions underneath or near the building.For example, piezometer measurements may be used by seismic detectionlogic to determine if the ground surrounding a building is at risk ofsoil liquefaction. In some cases, a building response signature mayinclude occupancy information which may be used to inform an alertsystem.

In some embodiments, by having sensors arrayed in both x and ydirections, seismic event detection logic may determine the direction ofseismic waves. In some cases, seismic event detection logic maydetermine the hypocenter of a seismic event using triangulation methods.As an example, consider a building with inertial sensors distributedalong 50 meters in both x and y directions. Since P-waves generallytravel between about 5 and 8 km/s, so long as inertial sensors have asampling frequency of at least 100 or 200 Hz, the direction of theseismic wave may be determined. When internal sensors have a much highersampling frequency, e.g., 2 kHz or 4 kHz, the time differential betweenwhen a seismic wave is measured at various sensors may be used todetermine the seismic hypocenter. In some cases, if the hypocenter of aseismic event is estimated using a measured P-wave, seismic logic mayalso determine and estimate the arrival of a subsequent S-wave.

In some embodiments, seismic event detection logic may determine if asensor is malfunctioning or needs to be replaced. For example, seismicevent detection logic may determine a sensor is not responding or isproviding erratic data by comparing the response of an individual sensorto the rest of a building response signature. When a sensor needs to bereplaced, seismic event detection logic may inform a buildingadministrator of the location of the malfunctioning sensor. In somecases, seismic event detection logic may calibrate a sensor, e.g.,adjust an offset of a sensor based on the collective inertial datameasurements recorded in a building response signature.

In some embodiments, seismic detection logic may be used to check thestructural integrity of a building and determine if a seismic retrofitis needed. For example, older buildings may be outfitted with inertialsensors as described herein. If a building response signaturecorresponding to a non-threatening event indicates a high risk of damageto seismic waves of a certain magnitude or seismic wave propagating froma certain direction, this information may be used by engineers to updatethe earthquake safety of a building. For example, seismic detectionlogic may look at the modes of resonance in a building during buildingmovement caused by windstorms and weak seismic waves. Seismic detectionlogic may aid in determining if a particular building component hasfailed—e.g., a foundation may no longer be stable, wooden components maybe compromised by dry rot, or particular joints may have failed. In somecases, seismic detection logic may be used to identify portions of abuilding that were not built according to code and/or building plans—forexample, if a contractor uses cheaper materials to save cost. Detectionof degradation in a building's structural integrity may be accomplishedin many ways. In some embodiments, the building's inertial sensor outputdata generated at defined intervals (e.g., daily at a set time) or overa longer period of time (e.g., continuously) is compared and flaggedwhen significant and consistent deviations are encountered. In somecases, filters are applied to capture only statistically significantdeviations. In some embodiments, building response signatures arecompared when generated by comparable stimuli (e.g., normal occupancy at10 am, winds out of the south at 50 mph, etc.). A significant change inthe response signature may indicate a degradation in structuralintegrity.

In some embodiments, seismic event detection logic may be used to informan active mass damper system when a building experiences lateral loads,as caused by wind or S-waves. For example, seismic detection logic mayrelay the current motion of the building, provided over a windownetwork, to an active mass damper so that the damping effect isimproved. Examples of mass damping systems that may be coupled toseismic detection logic include the vibration control systems producedby TESolution Co., Ltd. of Korea and the active damper system used inthe Taipei 101 building, in Taipei, Taiwan.

Installation Examples

Optically switchable windows, window controllers, and/or light sensorswith inertial sensors turn buildings into seismic event detectionsystems. These systems can be implemented in new building designs orused in older buildings where, e.g., a building is located in an area ofhigh earthquake risk. As described elsewhere, such window controlsystems may also be desired simply to acquire the aesthetic and climatemanagement benefits of optically switchable windows. Windows aretypically installed in frames that are anchored to the framing structureof a building. Window controllers are generally attached in the area ofa window; however, as discussed elsewhere herein, there is flexibilityin where they can be located. Windows may be installed in individualframes, or installed in a curtain wall or similar structure withmullions and transoms separating adjacent windows. All of thesecomponents may be considered to form the frame of a window. Typically,though not necessarily, the inertial sensors are affixed to structuralelements of the building, regardless of whether the sensors areassociated with a window assembly, window controller, or associated withanother device on the window network. (e.g., a rooftop light sensor).

Window Controllers and Window Networks Examples

Controllers used to control windows are described in U.S. patentapplication Ser. No. 15/334,835, filed Oct. 26, 2016, U.S. patentapplication Ser. No. 14/951,410, filed Jun. 2, 2016, U.S. patentapplication Ser. No. 13/449,248, filed Apr. 17, 2012, and U.S. patentapplication Ser. No. 13/449,251, filed Apr. 17, 2012, each of which isincorporated herein by reference in its entirety.

FIG. 4 depicts an example window controller 406 that may include logicand other features for controlling an optically switchable window.Controller 406 includes a power converter configured to convert a lowvoltage to the power requirements of an EC device of an EC lite of awindow. This power is typically fed to the EC device via a drivercircuit (power driver). In one embodiment, controller 406 has aredundant power driver so that in the event one fails, there is abackup, and the controller need not be replaced or repaired.

Controller 406 also includes a communication circuit (labeled“communication” in FIG. 4 ) for receiving and sending commands to andfrom a remote controller (depicted in FIG. 4 as “master controller”).The communication circuit also serves to receive and send input to andfrom a local logic device (e.g., a microcontroller). In one embodiment,the power lines are also used to send and receive communications. Themicrocontroller includes logic for controlling the at least one EC litebased on, e.g., input received from one or more sensors and/or users. Insome embodiments, a window controller may have associated sensors whichmay be external to the controller (sensors 1-3) or internal, or“onboard” the controller (sensors 4 and 5). These sensors may includeinertial sensors that are rigidly connected to the framing structure ofthe building and other sensors used by a window control system (e.g.,photosensors, temperature sensors, occupancy sensors, and the like). Inone embodiment, the controller uses the EC device as a sensor, forexample, by using current-voltage (I/V) data obtained by sending one ormore electrical pulses through the EC device and analyzing the feedback.This type of sensing capability is described in U.S. Pat. No. 9,454,055,naming Brown et al. as inventors, titled “Multipurpose Controller forMultistate Windows,” which is incorporated by reference herein in itsentirety. A window assembly may also include a PV cell, and thecontroller may use the PV cell not only to generate power, but also as aphotosensor. The microcontroller may also have logic for controllingwindow antenna functions.

In one embodiment, the controller includes a chip, a card, or a boardwhich includes appropriate logic, programmed and/or hard-coded, forperforming one or more control functions. Power and communicationfunctions of controller 406 may be combined in a single chip, forexample, a programmable logic device (PLD) chip, field programmable gatearray (FPGA) or similar device. Such integrated circuits can combinelogic, control and power functions in a single programmable chip. In oneembodiment, where the EC window (or window) has two EC panes, the logicis configured to independently control each of the two EC panes. If awindow is configured with a window antenna, the logic may also controltransmission and/or reception of signals. In one embodiment, thefunction of each of the two EC panes, and optional window antenna(s) iscontrolled in a synergistic fashion, that is, so that each device iscontrolled in order to complement the other. For example, the desiredlevel of light transmission, thermal insulative effect, antenna signaltransmission, and/or other property are controlled via a combination ofstates for each of the individual devices and/or antenna(s). Forexample, one EC device may have a colored state while the other is usedfor resistive heating, for example, via a transparent electrode of thedevice. In another example, the two EC device's colored states arecontrolled so that the combined transmissivity is the desired outcome.

Controller 406 may also have wireless capabilities, such as control andpowering functions. For example, wireless controls, such as RF and/or IRcan be used as well as wireless communication such as Bluetooth, Wi-Fi,ZigBee, EnOcean, LiFi (Light Fidelity) and the like to send instructionsto the microcontroller and for the microcontroller to send data out to,for example, other window controllers and/or a building managementsystem (BMS). Window antennas may be employed to send and/or receive thecontrol communications and/or power. Various wireless protocols may beused as appropriate. The optimal wireless protocol may depend on how thewindow is configured to receive power. For instance, if the window isself-powered through a means that produces relatively less power, acommunication protocol that uses relatively less power may be used.Similarly, if the window is permanently wired, for example with 24Vpower, there is less concern about conserving power, and a wirelessprotocol that requires relatively more power may be used. ZigBee is anexample of a protocol that uses relatively more power. Wi-Fi andBluetooth Low Energy are examples of protocols that use relatively lesspower. Protocols that use relatively less power may also be beneficialwhere the window is powered intermittently. LiFi refers to LightFidelity, which is a bidirectional, high-speed and networked wirelesscommunication technology similar to Wi-Fi. LiFi utilizes a light signal(e.g., visible light, infrared light, near-ultraviolet light, etc.) toconvey information wirelessly. The light signal may be too rapid and/ordim for human perception, though such signals can be easily perceived byappropriate receivers. In some cases, the LiFi signal may be generatedby one or more light emitting diode (LED), which may be coated with (orotherwise include) a material that allows for high data transmissionrates. Example materials may include perovskites. One particular examplematerial is cesium lead bromide (CsPbBr₃), which may be provided innanocrystalline form.

Wireless communication can be used in the window controller for at leastone of programming and/or operating the EC window and optionally thewindow antenna(s), collecting data from the EC window from sensors aswell as using the EC window as a relay point for wireless communication.Data collected from EC windows also may include count data such as anumber of times an EC device has been activated (cycled), the efficiencyof the EC device over time, and the like. Each of these wirelesscommunication features is described in U.S. Pat. No. 9,454,055, namingBrown et al. as inventors, titled “Multipurpose Controller forMultistate Windows,” previously incorporated by reference above.

In certain embodiments, light is used to communicate with and/or power awindow/antenna controller. That is, light generated at a distance by,for example, a diode laser transmits power and/or control signals to awindow controller via an appropriate light transmission medium such as afiber optic cable or free space. Examples of suitable photonictransmission methods for window controllers are described in PCTApplication No. PCT/US13/56506, filed Aug. 23, 2013, and titled“PHOTONIC-POWERED EC DEVICES,” which is herein incorporated by referencein its entirety. In a particular embodiment, power is provided throughphotonic methods, while communication is provided via one or more windowantennas patterned onto a lite of an electrochromic window or anassociated window component. In another embodiment, power is providedthrough photonic methods, while communication is provided via Wi-Fi oranother wireless communication method using antennas.

Returning to the embodiment of FIG. 4 , controller 406 may also includea RFID tag and/or memory such as solid state serial memory (e.g., I2C orSPI) which may optionally be a programmable memory. Radio-frequencyidentification (RFID) involves interrogators (or readers), and tags (orlabels). RFID tags use communication via electromagnetic waves toexchange data between a terminal and an object, for example, for thepurpose of identification and tracking of the object. Some RFID tags canbe read from several meters away and beyond the line of sight of thereader.

Most RFID tags contain at least two parts. One is an integrated circuitfor storing and processing information, modulating and demodulating aradio-frequency (RF) signal, and other specialized functions. The otheris an antenna for receiving and transmitting the signal.

There are three types of RFID tags: passive RFID tags, which have nopower source and require an external electromagnetic field to initiate asignal transmission, active RFID tags, which contain a battery and cantransmit signals once a reader has been successfully identified, andbattery assisted passive (BAP) RFID tags, which require an externalsource to wake up but have significant higher forward link capabilityproviding greater range.

In one embodiment, the RFID tag or other memory is programmed with atleast one of the following types of data: warranty information,installation information (e.g., absolute and relative position andorientation of the window), vendor information, batch/inventoryinformation, EC device/IGU characteristics, EC device cyclinginformation, inertial sensor information, and customer information.Examples of information that may be passed upstream from a windowcontroller, a BMS, or another device include the window voltage (V_(W)),window current (I_(W)), EC coating temperature (T_(EC)), glass visibletransmission (% T_(vis)), % tint command (external analog input fromBMS), digital input states, inertial measurements, and controllerstatus. The window voltage, window current, window temperature, and/orvisible transmission level may be detected directly from sensors on thewindows. The % tint command may be provided to the BMS or other buildingdevice indicating that the controller has in fact taken action toimplement a tint change, which change may have been requested by thebuilding device. This can be important because other building systemssuch as HVAC systems might not recognize that a tint action is beingtaken, as a window may require a few minutes (e.g., 10 minutes) tochange state after a tint action is initiated. Thus, an HVAC action maybe deferred for an appropriate period of time to ensure that the tintingaction has sufficient time to impact the building environment. Thedigital input states information may tell a BMS or other system that amanual action relevant to the smart window/antenna has been taken. Asdescribed elsewhere, inertial measurements may be collected as abuilding response signature and passed to seismic event detection logic.Finally, the controller status may inform the BMS or other system thatthe controller in question is operational, or not, or has some otherstatus relevant to its overall functioning.

Examples of downstream data from a BMS or other building system that maybe provided to the controller include window drive configurationparameters, zone membership (e.g. what zone within the building is thiscontroller part of), % tint value, digital output states, and digitalcontrol (tint, bleach, auto, reboot, etc.). The window drive parametersmay define a control sequence (effectively an algorithm) for changing awindow state. Examples of window drive configuration parameters includebleach to color transition ramp rate, bleach to color transitionvoltage, initial coloration ramp rate, initial coloration voltage,initial coloration current limit, coloration hold voltage, colorationhold current limit, color to bleach transition ramp rate, color tobleach transition voltage, initial bleach ramp rate, initial bleachvoltage, initial bleach current limit, bleach hold voltage, bleach holdcurrent limit. Examples of the application of such window driveparameters are presented in U.S. patent application Ser. No. 13/049,623(issued as U.S. Pat. No. 8,254,013), filed Mar. 16, 2011, and titled“CONTROLLING TRANSITIONS IN OPTICALLY SWITCHABLE DEVICES,” and U.S.patent application Ser. No. 13/449,251, filed Apr. 17, 2012, and titled“CONTROLLER FOR OPTICALLY-SWITCHABLE WINDOWS,” both of which areincorporated herein by reference in their entireties.

In one or more aspects, one or more of the functions described may beimplemented in hardware, digital electronic circuitry, analog electroniccircuitry, computer software, firmware, including the structuresdisclosed in this specification and their structural equivalentsthereof, or in any combination thereof. Certain implementations of thesubject matter described in this document also can be implemented as oneor more controllers, computer programs, or physical structures, forexample, one or more modules of computer program instructions, encodedon a computer storage media for execution by, or to control theoperation of window controllers, network controllers, and/or antennacontrollers. Any disclosed implementations presented as or for opticallyswitchable windows can be more generally implemented as or forswitchable optical devices (including windows, mirrors, etc.).

Various modifications to the embodiments described in this disclosuremay be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other implementationswithout departing from the spirit or scope of this disclosure. Thus, theclaims are not intended to be limited to the implementations shownherein, but are to be accorded the widest scope consistent with thisdisclosure, the principles and the novel features disclosed herein.Additionally, a person having ordinary skill in the art will readilyappreciate, the terms “upper” and “lower” are sometimes used for ease ofdescribing the figures, and indicate relative positions corresponding tothe orientation of the figure on a properly oriented page, and may notreflect the proper orientation of the devices as implemented.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or a variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this does not necessarily mean that the operations are requiredto be performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flow diagram. However, other operations thatare not depicted can be incorporated in the example processes that areschematically illustrated. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the illustrated operations. In certain circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the implementations describedabove should not be understood as requiring such separation in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products.Additionally, other implementations are within the scope of thefollowing claims. In some cases, the actions recited in the claims canbe performed in a different order and still achieve desirable results.

What is claimed is:
 1. A system for detecting seismic waves, the systemcomprising: two or more buildings, each comprising a plurality ofoptically switchable windows; a plurality of window controllers, eachconfigured to control the optical state of at least one of the pluralityof optically switchable windows, wherein the plurality of windowcontrollers are connected via a network; a plurality of inertial sensorscommunicatively coupled with the network, each configured to measureinertial data in at least one direction when affixed to a respective oneof the two or more buildings and to provide the measured inertial datato the network; and seismic event detection logic, operating on adistributed computing platform comprising at least one of the pluralityof window controllers, and configured to (i) identify or receivebuilding response signatures, wherein the building response signaturescomprise the measured inertial data from the plurality of inertialsensors and (ii) analyze the building response signatures to determinethat a seismic event has occurred.
 2. The system of claim 1, wherein theresponse signature of at least one of the two or more buildings furthercomprises location data for the plurality of inertial sensors.
 3. Thesystem of claim 1, wherein at least one of the plurality of inertialsensors is located within a mullion of one of the plurality of opticallyswitchable windows.
 4. The system of claim 1, wherein at least one ofthe plurality of inertial sensors is located within a housing for alight sensor, wherein the light sensor is connected with the network andconfigured to provide lighting information to the network forcontrolling the plurality of optically switchable windows.
 5. The systemof claim 1, wherein at least one of the plurality of inertial sensorscomprises an accelerometer or a gyroscope.
 6. The system of claim 5,wherein the accelerometer or the gyroscope has a sensitivity greaterthan about 0.5 V/g.
 7. The system of claim 5, wherein the accelerometeror gyroscope has a sampling frequency greater than about 1 kHz.
 8. Thesystem of claim 1, further comprising one or more additional sensorsselected from the group consisting of a strain gauge, an anemometer, atemperature sensor, a piezometer, a GPS sensor, and a camera, whereinthe one or more additional sensors provide additional data to thenetwork, and wherein the response signature of at least one of the twoor more buildings comprises the additional data.
 9. The system of claim1, wherein at least one of the plurality of inertial sensors isconfigured to provide inertial data to the network via a wirelessconnection to at least one of the plurality of window controllers. 10.The system of claim 1, wherein the network is further configured todeliver power to the plurality of window controllers and the pluralityof inertial sensors.
 11. The system of claim 1, wherein the seismicevent detection logic is further configured to determine that theresponse signature of at least one of the two or more buildingscorresponds to a P-wave.
 12. The system of claim 11, wherein the seismicevent detection logic is further configured to determine a seismichypocenter of the P-wave.
 13. The system of claim 11, wherein theseismic event detection logic is further configured to estimate anarrival of a corresponding S-wave.
 14. The system of claim 11, whereinthe seismic event detection logic is further configured to trigger analert after determining that the response signature of at least one ofthe two or more buildings corresponds to a P-wave, wherein triggeringthe alert includes one or more of providing audible or visual alerts tobuilding occupants, unlocking doors, closing gas lines, and closingwater lines.
 15. The system of claim 1, wherein the seismic eventdetection logic is further configured to determine that one or more ofthe plurality of inertial sensors is not functioning properly.
 16. Thesystem of claiml, wherein the seismic event detection logic is executedon a cloud computing platform in communication with the network.
 17. Thesystem of claim 1, wherein the seismic event detection logic is furtherconfigured to send control signals to the optically switchable windowsto: clear all the windows, clear only windows where occupants aredetected while other windows remain tinted, or tint windows to preventheat gain on one or more sides of a building when a cooling system isshut down, impaired, or expected to be impaired due to loss of power ormalfunction/damage from a seismic event.
 18. The system of claim 1,wherein the seismic event detection logic is configured to report to orreceive data from an external earthquake event detection network. 19.The system of claim 1, wherein the seismic event detection logic isconfigured to analyze the response signature of at least one of the twoor more buildings using a seismic model.
 20. The system of claim 19,wherein the seismic event detection logic is further configured todetect a structural change in at least one of the building two or morebuildings.
 21. The system of claim 20, wherein the seismic eventdetection logic is further configured to determine whether thestructural change creates a safety threat.
 22. The system of claim 21,wherein determining that the structural change creates a safety threattriggers one or more of providing audible or visual alerts to buildingoccupants, unlocking doors, closing gas lines, and closing water lines.23. A method for detecting seismic events, the method comprising:installing a respective window control system in each of two or morebuildings, the window control system comprising: a plurality ofoptically switchable windows, a plurality of window controllers, whereineach window controller is configured to control the optical state of atleast one of the plurality of optically switchable windows, and whereinthe plurality of window controllers are connected by a network, and aplurality of inertial sensors communicatively coupled with the networkand distributed in at least two dimensions in the building, wherein eachof the plurality of inertial sensors is configured to measure inertialdata in at least one direction, and wherein the plurality of inertialsensors is further configured to provide inertial data to the network;identifying a building response signature, wherein the building responsesignature comprises the inertial data provided to the network; anddetermining that a seismic event has occurred by analyzing, using aseismic event detection logic operating on a distributed computingplatform that comprises at least one of the plurality of windowcontrollers, the seismic event detection logic being configured to (i)identify or receive building response signatures from the two or morebuildings, wherein the building response signatures comprise themeasured inertial data from the plurality of inertial sensors and (ii)analyze the building response signatures to determine that a seismicevent has occurred.
 24. The method of claim 23, wherein the buildingresponse signature comprises location data for the plurality of inertialsensors.
 25. The method of claim 23, wherein at least one inertialsensor includes an accelerometer or gyroscope.
 26. The method of claim23, further comprising installing one or more additional sensors in atleast one of the one or more buildings, the one or more additionalsensors selected from the group consisting of a strain gauge, ananemometer, a temperature sensor, a piezometer, a GPS sensor, and acamera, wherein the one or more additional sensors provide additionaldata to the network.
 27. The method of claim 23, wherein detecting thata seismic event has occurred comprises detecting a P-wave when analyzingthe response signature of at least one of the two or more buildingsusing the seismic detection logic.
 28. The method of claim 23, furthercomprising detecting a structural change in at least one of the two ormore buildings.